ORGANOMETALLIC COMPOUNDS 345 the other methyls would involve a tertiary carbon, a process that does not occur very efficiently. CH iCu(CHs),+ Br H3 Lithiun 1.3, 3-Trimethylcyclopentene dimethylcyclope 14.10(b) Methylenecyclobutane is the appropriate precursor to the spirohexane shown CH,I Spiro[3.2 ]hexane(22%0) 14.11 Syn addition of dibromocarbene to cis-2-butene yields a cyclopropane derivative in which the methyl groups are cis C CHBr H, CI KoC(CHi) cis-2-Butene cis-l, l-Dibromo-2.3. Conversely, the methyl groups in the cyclopropane derivative of trans-2-butene are trans to one H3C CH trans-2-Butene trans-1, I-Dibromo-2.3. dimethylcyclopropane 14.12 Iron has an atomic number of 26 and an electron configuration of [Arl45-3do. Thus, it has 8 valence electrons and requires 10 more to satisfy the 18-electron rule. Five CO ligands, each providing two electrons, are therefore needed. The compound is Fe(co) 14.13 (a) Cyclopentyllithium is It has a carbon-lithium bond. It satisfies the requirement for classification as an organo- (b) Ethoxymagnesium chloride does not have a carbon-metal bond. It is not an organometallic CH, CHOMgC CH,CH,O Mg Cl (c) 2-Phenylethylmagnesium iodide is an example of a Grignard reagent. It is an organometallic Back Forward Main Menu TOC Study Guide Toc Student OLC MHHE Websitethe other methyls would involve a tertiary carbon, a process that does not occur very efficiently. 14.10 (b) Methylenecyclobutane is the appropriate precursor to the spirohexane shown. 14.11 Syn addition of dibromocarbene to cis-2-butene yields a cyclopropane derivative in which the methyl groups are cis. Conversely, the methyl groups in the cyclopropane derivative of trans-2-butene are trans to one another. 14.12 Iron has an atomic number of 26 and an electron configuration of [Ar]4s 2 3d6 . Thus, it has 8 valence electrons and requires 10 more to satisfy the 18-electron rule. Five CO ligands, each providing two electrons, are therefore needed. The compound is Fe(CO)5. 14.13 (a) Cyclopentyllithium is It has a carbon–lithium bond. It satisfies the requirement for classification as an organo￾metallic compound. (b) Ethoxymagnesium chloride does not have a carbon–metal bond. It is not an organometallic compound. (c) 2-Phenylethylmagnesium iodide is an example of a Grignard reagent. It is an organometallic compound. CH2CH2MgI CH3CH2OMgCl CH3CH2O Mg2 Cl or H Li C C H H3C CH3 H trans-2-Butene trans-1,1-Dibromo-2,3- dimethylcyclopropane CHBr3 KOC(CH3)3 H3C CH3 Br Br H H C C H H3C CH3 H cis-2-Butene cis-1,1-Dibromo-2,3- dimethylcyclopropane H3C CH3 Br Br H H CHBr3 KOC(CH3)3 CH2I2 Zn(Cu), ether CH2 Methylenecyclobutane Spiro[3.2]hexane (22%) LiCu(CH3)2 diethyl ether 1-Bromo-3,3- 1,3,3-Trimethylcyclopentene dimethylcyclopentene Lithium dimethylcuprate CH3 CH3 Br H3C CH3 CH3 ORGANOMETALLIC COMPOUNDS 345 Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website